Diagnostic significance of gastric cancer associated antigens (MG-AGS) in serum, ascitic fluid and gastric juice.

A group of monoclonal antibodies against gastric cancer, pooled in equal proportions, was used to investigate their corresponding antigens (MG-Ags) in serum and body fluid of patients with gastrointestinal cancer and benign diseases using microsphere-ELISA method. The mean serum level (plus 3 standard deviations) in 59 normal subjects was arbitrarily set as the positive threshold value. The positive rate was found to be 68.8% (135/196) in sera of patients with gastric cancer, 70% (14/20) in colonic cancer, 72.2% (24/33) in rectal cancer, 43.8% (7/16) in esophageal cancer, 45.5% (5/11) in cholecystic cancer and 34.9% (15/43) in lung cancer, which, however, was not found in primary liver cancer, pancreatic cancer and ovarian cancer. In 214 patients with benign diseases, a false positive rate was 7.48%. In gastric juice and ascitic fluid of patients with gastric cancer, the positive rates were found to be 61.7% (27/44) and 83.3% (20/24) respectively. These antigens were also determined repeatedly in sera of patients with gastric cancer who had undergone gastrectomy. It was found that the level of MG-Ags in sera began to decrease at 8-10 days after operation. These results suggest that the determination of MG-Ags is useful in the diagnosis of gastrointestinal cancer and evaluation of the treatments.

[Experimental study of the anti-tumor activity of CD3AK against human gastric cancer cell line in vitro and in vivo].

Human CD3AK and LAK cells were prepared from peripheral blood mononuclear cells (PBMC) by culturing them in recombinant IL-2 (rIL-2, 30 mu/ml) and anti-CD3 monoclonal antibody, and in rIL-2 alone (300/ml), respectively. By MTT assay, it was found that the PBMC, when cultured in the presence of anti-CD3/rIL-2, proliferated more actively and persistently than PBMC cultured in the presence of rIL-2 alone. In vitro cytotoxicity assay showed that CD3AK cells had stronger killing activity against a poorly differentiated human gastric adenocarcinoma cell line MNK 45 than LAK cells did. Winn's assay at an E/T ratio of 20 carried out in nude mice also indicated that CD3AK cells were more effective than LAK cells in tumor growth inhibition. When the nude mice were inoculated with MNK 45 admixed with CD3AK, none of them developed tumor whereas those inoculated with either MNK 45 or MNK 45 admixed with LAK cells all developed tumor. The results indicate that CD3AK would be a better choice than LAK for the adoptive immunotherapy of human stomach cancer.

[Effects of morphine on muscarinic receptors in limbic system in acute adjuvant-induced arthritic rats].

To induce arthritis, the adjuvant with heat-killed Mycobacterium tuberculosis was injected into the ankle joint in rats. Local redness, swelling, hotness, pain, and motor dysfunction of the inflamed joint (as well as mental dullness) were observed 48 h after inoculation. At this time, the maximal binding capacity (Bmax) of muscarinic receptors in limbic system was increased, while the dissociation constant (Kd) was unchanged. Injection of morphine (5 mg.kg-1) 3 times within 48 h after the inoculation resulted in a decrease of Bmax and an increase of Kd of M-receptors, together with diminution of pain and disappearance of dullness.

[Dynamic changes in depolarization of action potentials by high frequency stimulation in guinea pig papillary muscles].

The effect of high frequency stimulation on rate-dependent depression of depolarization of action potentials was studied with computer and standard microelectrode techniques in guinea pig papillary muscles. After increasing driving frequency from 0.5 to 6 Hz, decreases in Vmax, APA and OS were found. Changes of upstroke velocity during phase 0 between driving frequency 6 and 0.5 Hz could be described as a parabola. The rate-dependent depression of depolarization was exaggerated by tetrodotoxin (TTX), particularly during the accelerating period of phase 0. A progressive decline in Vmax, which could be fitted by a power function curve, was observed after changing driving frequency from 1 to 5 Hz. TTX significantly influenced the decline in Vmax and the regression coefficients in fitted equations.